FIG 6.

GluR-GluK indirectly regulated antibiotic biosynthesis in S. coelicolor. (A) Phenotypic analysis of overexpression of the gluABCD gene cluster in the ΔgluR-K mutant on MM with 75 mM glutamate. The gluABCD gene cluster was under the control of the strong constitutive promoter ermE*p. M145/pIB139 and ΔgluR-K/pIB139 strains were used as a positive and a negative control, respectively. The images were photographed from the back at 48 and 96 h. (B) EMSA of GluR binding to the respective promoter regions of cluster-situated regulatory genes of these three different antibiotics (ACT, yCPK, and RED). The assays were performed using the indicated amounts of purified His₆ tag-GluR protein (micrograms) and Cy5 fluorescence-labeled promoter probes.